Bis[4-(4-pyridyl)pyridinium] (4-carboxy­pyridine-2,6-dicarboxyl­ato-κ3O2,N,O6)(pyridine-2,4,6-tricarboxyl­ato-κ3O2,N,O6)ferrate(III) trihydrate

In the title salt, (C10H9N2)2[Fe(C8H2NO6)(C8H3NO6)]·3H2O, the FeIII atom is O,N,O′-chelated by dianionic and trianionic ligands in a slightly distorted octa­hedral coordination geometry. The cations and ferrate anions are linked into a layered structure; the layers are connected through the uncoordinated water mol­ecules into a hydrogen-bonded three-dimensional supra­molecular structure. One of the uncoordinated water molecules is disordered around an inversion centre and was refined with half-occupancy for each position.